ABSTRACT
BACKGROUND: Correction of residual myopia after radial keratotomy may be attempted with repeated keratotomy surgery, but predictability can be less than satisfactory. Excimer laser photorefractive keratectomy (PRK) provides an alternative approach to improving the refractive result in these patients. METHODS: Twenty-five eyes of 20 patients at five clinical locations underwent PRK for residual myopia after radial keratotomy. The number of incisions ranged from 4 to more than 16. Clear zones ranged from 3 mm to 4 mm. Best corrected visual acuity was 20/20 or better in 16 of the 25 eyes, with a range from 20/12 to 20/80. Uncorrected visual acuity was 20/200 or worse in 15 of the 25 eyes, with a range from 20/25 to finger counting. The interval between radial keratotomy and PRK averaged 33.5 months, with a range from 5 to 96 months. Nineteen eyes had 6 months or more of follow up; 15 had 12 months or more. RESULTS: Corneal haze was maximal 1 month after surgery (mean +/- SE, 0.65 +/- 0.09), and declined to 0.35 +/- 0.16 at 12 months. Twelve months after PRK, mean keratometric readings were 40.19 +/- 0.81 diopters (D) and mean spherical equivalent refraction was -1.42 +/- 0.47 D. Nine (60%) of the 15 eyes with 12 months follow up were within 1 D of emmetropia and 12 (80%) were within 2 D. Eight (53%) of the 15 eyes had uncorrected visual acuities of 20/40 or better. Spectacle-corrected visual acuity in the eyes with 12 months follow up improved in 4, did not change in 4, and worsened in 6. CONCLUSIONS: The results of PRK are less predictable in eyes that have previously undergone radial keratotomy, and these eyes respond with more haze after PRK than normal eyes.
Subject(s)
Cornea/surgery , Keratotomy, Radial/adverse effects , Myopia/surgery , Photorefractive Keratectomy , Adult , Cornea/physiology , Corneal Opacity/etiology , Corneal Opacity/physiopathology , Eyeglasses , Female , Follow-Up Studies , Humans , Lasers, Excimer , Male , Middle Aged , Myopia/etiology , Photorefractive Keratectomy/adverse effects , Reoperation , Visual Acuity/physiologyABSTRACT
Clinical and morphologic features are described in two patients known to have repeatedly injected intravenously talc-containing drugs intended for oral use. In one patient severe pulmonary hypertension developed; the talc granulomas in him were located predominantly within the pulmonary arteries. The second patient had normal pulmonary arterial pressures, and the talc granulomas in him were located predominantly in the pulmonary interstitium. Of 19 previously described patients with pulmonary talc granulomas, 12 had morphologic evidence of pulmonary hypertension (in three of severe degree); in each, talc granulomas were located predominantly within the pulmonary arteries. In those without signs of pulmonary hypertension, granulomas were located predominantly in the pulmonary interstitium. Why there are differences in the distribution of the talc granulomas is unclear. It is clear, however, as demonstrated by one of our patients, that severe pulmonary hypertension may be a consequence of intravenous injection of drugs intended for oral use.
